Les torsades des pointes

A 17-year-old woman had two admissions within five months for recurrent episodes of ventricular tachycardia in conjunction with a prolonged QT interval. On both occasions these were refractory to intravenous lidocaine and bretylium. During her first admission her dysrhythmia was controlled by repeated doses of intravenous propranolol; however, she required temporary overdrive transvenous pacing on her second admission. On both occasions when the low normal serum potassium was replaced and therapeutic levels of diphenylhydantoin and phenobarbital were obtained, the episodes of ventricular tachycardia subsided. This case illustrates the complexities inherent in making the diagnosis and in treating this syndrome, and should assist the emergency physician in treating this difficult and potentially fatal dysrhythmia.